1. Field of the Invention
The present invention relates to a chip-antenna. More particularly, the present invention relates to a chip-antenna for use in a low-frequency band radio equipment such as a television, a radio, a pager, for example.
2. Description of the Related Art
In FIG. 12, a monopole antenna 100 as a representative wire antenna is shown. This monopole antenna 100 has a radiating element 102 set up substantially perpendicular to the grounding surface 101 in air (dielectric constant .epsilon.=1, relative magnetic permeability .mu.=1). And, a feeding power supply V is connected to one end 103 of this radiating element 102, and the other end 104 is kept open.
However, in the case of the above-mentioned conventional monopole antenna, as the radiating element of the antenna is placed in the air, the dimensions of the radiating element of the antenna become large. For example, assuming that the wavelength in the air is .lambda., a radiating element having a length of .lambda./4 is required and then the length of the radiating element of a monopole antenna becomes as long as about 40 mm for a 1.9 GHz band. Further, the bandwidth of a monopole antenna having a reflection loss of less than -6 (dBd) is as narrow as about 30 MHz. Accordingly, there has been a problem that it is difficult to use the monopole antenna in the cases where a small-sized and wide-band antenna is needed.